Messier 85 (NGC 4382)
J2000 coordinates, SBF distance (58.7 Mly), magnitude 9.10, concentric stellar shells, NGC 4394 companion pair, and observing guide for Messier 85.
Provenance-Backed Scientific Measurements
Every measurement below preserves its unit, uncertainty interval, observational method, reference epoch, quality status, and primary catalog source. See Uncertainty & Provenance for how competing measurements are handled.
| Parameter | Value | Uncertainty | Method & Epoch | Quality Status | Source Archive |
|---|---|---|---|---|---|
| Integrated visual magnitude (V) | 9.1 mag | ± 0.08 mag | Integrated CCD aperture photometry | definitive | Revised New General Catalogue and Index Catalogue (RNGC/IC) |
| Distance in light-years | 58700000 ly | ± 2000000 ly | HST ACS Virgo Cluster Survey surface-brightness fluctuations (18.0 ± 0.6 Mpc) | definitive | SH0ES Local Distance Ladder Hubble Constant |
| Apparent major axis | 7.1 arcmin | ± 0.3 arcmin | Optical isophotal dimensions (7.1′ × 5.2′) | definitive | Revised New General Catalogue and Index Catalogue (RNGC/IC) |
| Heliocentric recession velocity | 729 km/s | ± 5 km/s | Optical stellar absorption spectroscopy | definitive | SIMBAD Astronomical Database (CDS) |
J2000 Equatorial Sky Chart & Culmination Altitude
The chart below plots Messier 85 (NGC 4382 Merger-Remnant S0) at RA 12h 25m 24.05s, Dec +18° 11′ 27.9″ within Coma Berenices, alongside peak meridian transit altitudes for 40°N and 30°S observers. Use the RA/Dec Coordinate Converter to compute exact culmination altitude for your latitude.
Astrophysical Context & Structure
Discovered by Pierre Méchain on March 4, 1781, and confirmed by Charles Messier two weeks later, Messier 85 (NGC 4382) is the northernmost member of the Virgo Galaxy Cluster in the Messier catalog, lying 58.7 million light-years away across the border in southern Coma Berenices. Shining at visual magnitude 9.10 and spanning ~121,000 light-years across, M85 is classified as a peculiar lenticular galaxy (SA(s)0+ pec) virtually devoid of cold neutral hydrogen gas.
Deep optical imaging reveals why M85 carries the 'peculiar' designation: its outer stellar envelope is rippled with concentric shells, tidal ripples, and asymmetric plumes, while spectroscopic line-strength maps detect a young, 2-to-3-billion-year-old stellar ring in its core. These features prove that M85 experienced a wet galaxy merger roughly 2.5 billion years ago that consumed the remaining gas in a central starburst before leaving the remnant quiescent.
M85 has produced two celebrated optical transients: the classical Type Ia supernova SN 1960R and the enigmatic May 2006 transient M85 OT2006-1—the prototype of 'luminous red novae' caused by the common-envelope stellar merger of two main-sequence stars. Just 7.8 arcminutes east of M85 sits its physical companion NGC 4394, a classic 10.9-magnitude barred spiral galaxy.
Practical Visual Observing Guide
- Situated in southern Coma Berenices, 5.3° north of M84/M86 and 1°east-northeast of the 4.8-mag star 11 Comae Berenices.
- Always observe M85 at medium magnification (60×–110×) in a 100–200 mm telescope so you can frame both the bright, oval 9.1-mag lenticular M85 and its 10.9-mag barred spiral companion NGC 4394 just 7.8′ to the east.
- A 13th-magnitude foreground Milky Way star is superimposed just north of M85's bright nucleus, frequently startling observers who mistake it for a new supernova.
Catalog Cross-Identifications & Aliases
Common Aliases: M85 · NGC 4382 · UGC 7508 · PGC 40515
| Catalog Authority | Identifier |
|---|---|
| MESSIER | M 85 |
| NGC | NGC 4382 |
| SIMBAD | M 85 |
| WIKIDATA | Q14033 |
Related Objects, Comparisons & Guides
Messier 84 (NGC 4374 Markarian Chain Core)
J2000 coordinates, SBF distance (54.8 Mly), magnitude 9.10, western Markarian's Chain anchor, twin radio jets, and observing guide for Messier 84.
Messier 86 (NGC 4406 Blueshifted Lenticular)
J2000 coordinates, SBF distance (55.4 Mly), magnitude 8.90, −244 km/s blueshift, ram-pressure X-ray plume, and observing guide for Messier 86 in Virgo.
Mirror Galaxy (Messier 100 / NGC 4321)
J2000 coordinates, HST Cepheid distance (53.8 Mly), magnitude 9.35, grand-design spiral arms, five supernovae, and observing guide for Messier 100.
Angular Size, Separation & Field of View
How angular diameter (degrees, arcminutes, arcseconds), spherical angular separation, and small-angle physical diameter relate to telescope field of view.
Apparent vs Absolute Magnitude Explained
Understand the logarithmic Pogson astronomical magnitude scale, apparent visual magnitude (m), absolute magnitude (M at 10 parsecs), and bolometric corrections.
Scientific Sources & Dataset Provenance
- Revised New General Catalogue and Index Catalogue (RNGC/IC) (2024/2026 edition): Steinicke, W. 2010, Observing and Cataloguing Nebulae and Star Clusters (Cambridge Univ. Press); Verga, M. OpenNGC (CC-BY-SA 4.0 / data tables) — Wolfgang Steinicke / OpenNGC
- SH0ES Local Distance Ladder Hubble Constant (2022 Baseline Cepheid + SN Ia): Riess, A. G., et al. 2022, ApJL, 934, L7 (A Comprehensive Measurement of the Local Value of the Hubble Constant) — SH0ES Collaboration (HST / JWST)
- SIMBAD Astronomical Database (CDS) (2026-10 release): Wenger, M., et al. 2000, A&AS, 143, 9 (The SIMBAD astronomical database) — Centre de Données astronomiques de Strasbourg